TY - JOUR
T1 - Orbital Instability of Standing Waves for the Coupled Nonlinear Klein-Gordon Equations
AU - Shulin Zhou , Boling Guo  & Jian Zhang 
JO - Journal of Partial Differential Equations
VL - 4
SP - 303
EP - 314
PY - 2008
DA - 2008/11
SN - 21
DO - http://doi.org/
UR - https://global-sci.org/intro/article_detail/jpde/5284.html
KW - Orbital instability
KW - standing wave
KW - coupled Klein-Gordon equations
KW - invariant set
AB -  This paper deals with a type of standing waves for the coupled nonlinear Klein-Gordon equations in three space dimensions. First we construct a suitable constrained variational problem and obtain the existence of the standing waves with ground state by using variational argument. Then we prove the orbital instability of the standing waves by defining invariant sets and applying some priori estimates.